Pushbutton switch control assembly with flexible cord or equivalent allowing operation of one pushbutton and associated switch at a time

ABSTRACT

A pushbutton control assembly for operating a vehicle&#39;&#39;s heating, ventilating, and air conditioning system cmprises a housing having a movable valve for operating a plurality of fluid motors and electrical switch contacts for operating a plurality of electrical devices, the valve being adjustable by means of a single slide member the position of which is determined by a selected one of a number of reciprocable pushbuttons which also effect opening and closing of selected switch contacts. A flexible motion transmitting cord is coupled to all of the pushbuttons and is operable to effect movement of a selected pushbutton in one direction in response to movement of any other pushbutton in the opposite direction.

United States Sandi et al.

Patent [191 Schawinsky, South Lyon, both of Mich.

Essex International, Inc., Fort Wayne, Ind.

Filed: Jan. 7, 1972 Appl. N0.: 216,065

Assignee:

U.S. Cl. 200/5 E, ZOO/50 C, 74/483 PB Int. Cl. H01h 9/26 Field of Search200/5 E, 5 EA, 5 EB,

200/5 OC, 5 R; 74/483 PB 1 References Cited UNITED STATES PATENTS [451July 17, 1973 2,320,774 6/1943 Flynt 200/5 EA 3,205,318 9/1965 Bilek200/5 E 3,268,673 8/1966 Bilek 200/5 E 3,183,315 5/1965 Kiely 200/5 EB1,370,304 8/1932 Wentzel 200/5 E X Primary Examiner-J. R. ScottAttorney-John F. Learman,.l0hn K. McCulloch et a1.

[57] ABSTRACT A pushbutton control assembly for operating a vehiclesheating, ventilating, and air conditioning system cmprises a housinghaving a movable valve for operating a plurality of fluid motors andelectrical switch contacts for operating a plurality of electricaldevices, the valve being adjustable by means of a single slide memberthe position of which is determined by a selected one of a number ofreciprocable pushbuttons which also effect opening and closing ofselected switch contacts. A flexible motion transmitting cord is coupledto all of the pushbuttons and is operable to effect movement of aselected pushbutton in one direction in response to movement of anyother pushbutton in the opposite direction.

PUSIIBUTTON SWITCII' CONTROL ASSEMBLY WITH FLEXIBLE CORD OR EQUIVALENTALLOWING OPERATION OF ONE PUSHBUTTON AND ASSOCIATED SWITCI-I AT A TIMEThe invention disclosed herein relates to pushbutton operated apparatusespecially adapted for controlling the operation of a vehicle s heating,ventilating, and air conditioning system of thekind having certaincomponents operated-by fluid pressure and other components operatedelectrically. Operation of the fluid pressure components is controlledby a shiftable instrumentality and operation of the electricalcomponents is controlled by the making and breaking of electricalcircuits. Control apparatus constructed according to the inventionincludes a plurality of reciprocable pushbuttons which are operable toeffect movements of the fluid pressure control instrumentality'andmaking and breaking of the electrical circuits.

Heating, air conditioning, and ventilating apparatus included inautomotive vehicles conventionally have a plurality of air ductsprovided with doors for controlling the flow of air through the ducts.The positions of such doors conventionally are controlled by fluidactuated devices which, in turn, are controlled by an adjustableinstrumentality such as a valve interposed between the fluid actuateddevices and a source of fluid. The flow of air through the ducts to theheater and air conditioner units also is regulatedby means ofelectrically operated, multiple-speed blowers, the operation of whichare controlled by manually operated switches. The air conditioningunitconventionally includes an electrically operated, magnetic clutchfor coupling and uncoupling the air conditioner compressor to and fromthe vehicle engine by means of manually operated switches.

A typical vehicle air conditioning, heating, and ventilatingsystem,together with its operating controls and ducts, is disclosed in US Pat.No. 2,914,629 granted Nov. 24, 1959, and to which reference may be hadfor a more detailed description of the system.

The control apparatus for the system disclosed inthe aforementionedpatent functions satisfactorily, but includes a large number of'partsheretofore deemed essential to provide the necessary control'over thevariouscomponents ofthe heating, ventilating, and air conditioningsystem. The'inclusion of a large number of parts increases the cost ofsuch controlapparatus, not only because of the necessity ofmanufacturing such parts, but also because of the time required in theirassembly. Moreover, the provision of alarge number of parts in 'acontrol device of the kind referred to requires the expenditure ofconsiderable force to effect adjustmerit of the controlapparatus fromone condition to another inasmuch as sufficient force must be applied toeffect movement of all, or most, of such parts. The inclusion ofmultiple parts also increases the likelihood of failure of the controlapparatus due to wear or imperfections in manufacture and assembly ofsuch parts.

An object of this invention is to provide control apparatus foravehicles heating, ventilating, and air conditioning system and whichovercomes the disadvantages of prior art apparatusfor similar purposesby substantially reducing the numberof parts required.

Another object of the invention is to provide control apparatus of thekind referred to having manually operable, reciprocable pushbuttons anyone of which may be moved manually in one direction, and provided withimproved means for returning such pushbutton to its original position inresponse to manual movement of any other pushbutton.

A further object of the invention is to provide a pushbutton controlassembly of the character described and wherein each pushbutton iscapable of operating both the fluid pressure and electrical componentsof a system.

Other objects and advantages of the invention will be pointed outspecifically or will become apparent from the following description whenit is considered in conjunction with the appended claims and theacompanying drawings, in which:

FIG. 1 is a longitudinal sectional view taken substantially along theline 1--1 of FIG. 2 and illustrating a pushbutton control deviceconstructed in accordance with the invention and with the parts thereofin one position of adjustment;

FIG. 2 is a bottom plan view of the apparatus, with parts broken awayfor clarity of illustration;

FIG. 3 is a transverse sectional view taken on the line 3-3 of FIG. 1;

FIG. 4 is a view similar to FIG. 1, but illustrating the apparatus in adifferent position of adjustment;

FIG. 5 is a fragmentary view of a portion of the apparatus shown in FIG.4 and illustrating the parts in another position of adjustment;

FIG. 6 is a view similar to FIG. 5, but illustrating the parts in stillanother position of adjustment; and

FIG. 7 is a plan view of electrical busses forming part of theapparatus.

A control device constructed in accordance with the invention comprisesa casing or housing 1 composed of two halves 2 and 3 formed ofelectrically insulating material such as nylon or the like andmaintained in assembled relation by suitable means such as rivets, oneof which is shown at 4a in FIG. 3. The casing half 2 has a base4provided with a plurality of passages 5 comm unicating with an interiorchamber 6, each of the passages also communicating with tubular fittings7 carried by and projecting outwardly from the base 4. One of thefittings is adapted for connection toa pressure or vacuum fluid sourceand the others are adapted for connection to fluid motors of the kindcapable of operating air duct doors or valves.

Slidably accommodated in the chamber 6 is a metal-- lic carrier 8 withinwhich is received a rubber instrumentality or valve 9 having a pluralityof passages 10 confronting the passages 5. A spring 11 reacts betweenable communication to be established among selected.

ones of the passages 5 to the exclusion of the others, depending uponthe position of the valve 9 in the chamber 6.

A single slide member 12 is mounted in a recess 13 formed adjacent theside wall of the casing half 2 and comprises a body 14 formed of nylonor other suitable insulating material having a driving stud l5 fittedinto an openingformedin the carrier 8 so as to couple the valve and theslide 12 for conjoint reciprocating movements along a path defined bythe recess 13. The recess 13 has a bottom wall 16 on which the loweredge of the slide body 14 bears throughout its length. The upper oropposite edge of the slide body 14 has a plurality of spaced, generallyV-shaped notches l7, 18, 19, 20, 21,

and 22 formed therein, the sides of the notches being contoured to formcams for a purpose subsequently to be explained.

The casing half 3 has a base 23 on the inner surface of which aremounted electrical buses 24, 25, and 26. The bus 24 has three mountingfeet 27, 28 and 29 which are secured to the base 23 by rivets 30, 31,and 32, respectively. The bus 25 has mounting feet 33 and 34 secured tothe base by rivets 35 and 36, respectively, and the bus 26 has mountingfeet 37 and 38 secured to the base by rivets 39 and 40, respectively.The bus 24 has six integral, resilient, electrically conductive contactleaves 41, 42, 43, 44, 45, and 46, each of which has an undulatingconfiguration in cross-section as is best shown in FIG. 3. The bus 25has four contact leaves 47 50 which are similar to and confront theleaves 41 44, respectively. The bus 26 has a pair of similar contactleaves 51 and 52 which confront the leaves 45 and 46, respectively. Theconfronting leaves of each pair of contacts are spaced apart from oneanother, and the configuration of each leaf is such that, at the freeends of each pair of confronting leaves, is a constricted throat 53(FIG. 3) leading to an enlarged chamber 54. The free ends of the contactleaves thus constitute detent means for a purpose presently to beexplained.

The bus mounting foot 28 is connected by its rivet 31 to a terminal 55which may be connected by wiring to the positive side of a battery (notshown). The mounting foot 34 of the bus 25 is connected by its rivet 36to a terminal 56 and the foot 37 of the bus 26 is connected by its rivet39 to a third terminal 57. The terminals 56 and 57 may be connected tothe negative side of the battery through high speed and low speedterminals, respectively, of an electric blower (not shown).

Normally, none of the pairs of contact leaves are in engagement so thateach pair of contact leaves constitutes a normally open switch, but whenthe leaves of any pair of contacts are closed or bridged by a conductor,a circuit will be established through the terminal 55, and one of theterminals 56 or 57.

A pair of terminals 58 and 59 is mounted on the base 4 of the casinghalf 2 by means of rivets 60 and 61 which also mount electricallyconductive spring arms 62 and 63 thatextend inwardly of the casing l andare provided with contacts 64 and 65 at their free ends. Adjacent theirfree ends, the arms 62 and 63 are bent to form cam surfaces 66 and 67,respectively, for a purpose hereinafter to be explained. The contacts 64and I 65 normally are disengaged, but may be moved into engagement toestablish a circuit between the terminals 58 and 59. These terminals maybe connected to a magnetic clutch (not shown) of a conventional vehicleair conditioner compressor through a battery or other source ofelectrical energy.

The casing halves 2 and 3 have top walls 68 and 69, respectively, whichare relieved at corresponding intervals to form six openingscommunicating with the interior of the casing. Slidably mounted in theopenings are six reciprocable pushbuttons 70, 71, 72, 73, 74, and 75. Atthe inner end of the pushbutton 70 is an extension 76 that is adapted topass between the confronting contact leaves 41 and 47. The otherpushbuttons 71 75 have similar extensions 77 81, respectively, which areadapted to pass between the confronting leaves of their associatedcontacts. Each of the extensions is pierced adjacent its free end forthe accommodation of a double-headed, electrically conductive contact82, but the contact 82 is omitted from the extension 76 so as to form anopening 82a (FIG. 4). However, each of the contact leaves 41 and 47associated with the extension 76 is provided with an indentation ordimple 83 so positioned as to be capable of entering the opening 82awhen the extension 76 is in the retracted position shown in FIG. 1.

Straddling each of the pushbuttons 70 75 are guide blocks 84 which guidethe pushbuttons in their reciprocating movements.

The guide blocks 84 are formed integrally with the casing half 2.

The apparatus includes a flexible, non-elastic, motion transmitting cord85 which extends alongside the push buttons 70 75 and rests against theguide members 84. The length of the cord 85 exceeds the distance spannedby the pushbuttons 70 75 and the excess length of the cord correspondssubstantially to twice the travel of any of the pushbuttons. Theopposite ends of the cord are clamped in anchor members 86 carriedadjacent opposite ends of the casing 1.

Each of the pushbuttons 70 4 75 includes a laterally projecting couplingstud 87 which bears. against the cord 85 but on the opposite sidethereof from the guides 84. Each pushbutton also carries a second stud88 having a wedge-shaped shifter extension 89 which overlies theassociated notches 17 22 formed in the slide body 14. The shifters 89areso positioned as to be capable of engaging at least one edge of theirassociated notches.

The parts of the apparatus are illustrated in FIG. 1 in the positionsthey occupy when the heater, defroster, and air conditioner of a vehicleare inoperative and the fresh air vent is closed. In these positions ofthe parts, all pushbuttons occupy an outwardly projected position,except the pushbutton which may bear the notation OFF, and which isdepressed or retracted into the casing 1 so that its extension 76 liesbetween the contact leaves 41 and 47 with the dimples 83 accommodated inthe opening 82a. The dimples 83 and the opening thus constitutecooperable detents for releasably latching the pushbutton 70 in itsretracted position.

In the retracted position of the pushbutton 70 the as sociated shifter89 is at the bottom of the notch 17, thereby maintaining the slide 12 inthe extreme' lefthand positionand preventing inadvertent movement of theslide 12 and the valve 9 from the positions shown in FIG. 1. In thisposition of the pushbutton 7.0a portion of the cord 85 is displacedinwardly of the casing by the associated stud 87 so as to take up theslack created by the excess length of the cord. The cord, therefore, ismaintained taut and precludes inadvertent retraction or rattling of anyof the other pushbuttons. The studs 87 cooperate with the casing wall 68to limit outward movement of the pushbuttons.

If it is desired to operate the vehicles defroster the pushbutton 75,bearing the notation DEF" may be depressed and moved from the positionshown in FIG. 1 to the position shown in FIG. 4. As the pushbutton isretracted, its stud 87 will bear against the cord to move the latterinwardly of the casing between the adjacent guides 84. The cord 85 thuswill be stressed longitudinally causing it to exert a force on thepushbutton 70 to move the latter outwardly of the casing, therebywithdrawing the extension 76 from between the contact blades 41 and 47and withdrawing the shifter 89 from the notch 17. As the pushbutton 75continuesto move inwardly of the casing its shifter 89 will engage awall of the notch 22 and shift the slide 12 and the valve 9 to the rightfrom the positions shown in FIG. 1 to the positions shown in FIG. 4.Those passages 5 associated with the doors of the ducts leading to thevehicles defroster thus will be manipulated so as to enable air to flowto the defroster outlets. Simultaneously with the shifting of the slide12, the extension 81 of the pushbutton 75 will be introduced between theconfronting contact blades 46 and 52 thereby enabling the conductor 82to bridge the contact blades and establish a circuit via the terminals55 and 57 to the defroster blower. The detenting action between thecontact blades 46 and 52 and the conductor 82 will maintain thepushbutton 75 in its retracted position and the engagement between theshifer 89 and the walls of the notch 22 will maintain the slide 12 andthe valve 9 in their adjusted position.

Any one of the other pushbuttons 71 74 may be depressed in the samemanner described in connection with the pushbutton 75. i

The pushbuttons 71 and 72 control the vehicles air conditioning unit andmay bear the notations MAX A/C" and A/C", respectively. Depression ofthe pushbutton 71 when the slide 12 is in the position shown in FIG. 1establishes a circuit via the contact leaves 42 and 48 and the terminals58 and 59 to the blower, but the notch .18 is so contoured that theslide 12 is not shifted. Thus, the doors of the air ducts will remain inthe same positions they occupy when the OFF pushbutton is depressed soas to enable the air within the vehicle to be circulated through the airconditioning unit without the introduction of fresh air. As thepushbutton 71 is depressed the stud 88 associated therewith engages thecam surface 66 on the contact leaf 62 and earns the latter toward theleaf 63 so as to engage the contacts 64 and 65 as is shown in FIG. 5. Acircuit thus may be completed through the terminals 58 and 59 to themagnetic clutch of the air conditioner so as to operate the compressor.

If it is desired to permit fresh air to be circulated through the airconditioner, the A/C" pushbutton 72 may be depressed to complete acircuit via the contact leaves 43 and 49 to the blower and to cam theleaf 63 toward the leaf 62 so as to close the'contacts 64 and 65 andcomplete a'circuit to the magnetic clutch of the air conditioning unit.These are the positions of the parts shown in FIG. 6. As the pushbutton72 is depressed, its shifter 89 will engage the wall of the notch 19 soas to shift the slide 12 to the right from the position shown in FIG. 1,thereby establishing communication between those passages 5 which enablea door in the air duct to be adjusted in such manner as to permit freshair to enter the interior of the vehicle.

Depression of the VENT" pushbutton 73 will establish a circuit via thecontact blades 44 and 50 to the vehicle blower and will effect shiftingof the slide 12 to a position in which fresh air may be admitted to theinterior of the vehicle. When the VENT? pushbutton is depressed, theslide 12 occupies the same position that it occupies when the A/C"pushbutton 72 is depressed.

Depression of the HEAT" pushbutton 74 will establish a circuit to theblower via the contact blades 45 and 5! and will shift the slide 12 to aposition such that the passages 5 which control theair duct door controlwill locate the door in a position to direct airthrough the heater unit.

Regardless of which one of the several pushbuttons is depressed, itsmovement inwardly of the casing will cause corresponding simultaneousoutward movement via the cord of any previously depressed pushbutton,and the configuration of the wallsof the notches in the slide are suchthat the slide may be shifted by the pushbutton being depressed withoutinterference from the pushbutton being returned to its projectedposition. Since only one slide is required in control apparatusconstructed in accordance with the invention, the max imum force whichmust be applied to any pushbutton to depress does not exceed thatnecessary to shift the single slide, the valve, spread the contactleaves associated with the pushbutton, and restore the previouslydepressed pushbutton.

The disclosed embodiment is representative of a presently preferred formof the invention, but is intended to be illustrative rather thandefinitive thereof, The invention is defined in the claims.

We claim:

1. Pushbutton control apparatus comprising valve means movable between aplurality of positions; a slide member mounted for back and forthmovements along a path; means coupling said slide member to said'valvemeans for moving the latter in response to movements of said slidemember; a plurality of pushbuttons mounted for back and forth movementsalong a path lateral of the path of movement of said slide member;cooperable means on said slide member and on each of said pushbuttonsengageable in response to movement in one direction of a selected one ofsaid pushbuttons to effect movement in a selected direction of saidslide member; means flexible in the path of movement of and spanningsaid pushbuttons and having a length greater than the distance spannedby said pushbuttons; and means coupling said flexible means to each ofsaid pushbuttons operable in response to movement in said one directionof any other one of said pushbuttons to impart movement of said selectedone of said pushbuttons in the opposite direction to disengage thecooperable means on said slide member and said selected one of saidpushbuttons. I

2. Apparatus according to claim 1 wherein said flexible means comprisesa cord.

3. Apparatus according to claim 1 wherein the excess length of saidflexible means corresponds substantially to twice the length of travelof a pushbutton.

4. Apparatus according to claim 1 including guide means straddling eachof said pushbuttons and engaging said flexible means, said couplingmeans including a part carried by each of said pushbuttons forengagement with said flexible means between adjacent guide means.

5. Apparatus according to claim 4 wherein said flexible means extendsalongside all of said pushbuttons and wherein said part comprises aprojection extending from and overlying said flexible means.

6. Apparatus according to claim 1 wherein said cooperable meanscomprises a cam surface on said slide member in the path of movement ofand engageable by said selected one of said pushbuttons.

7. Apparatus according to claim 6, wherein said slide member has a camsurface in the path of movement and engageable by each of saidpushbuttons, said cam surfaces being so contoured that the engagementbetween a selected one of said cam surfaces and the associatedpushbutton effects predetermined movement of said slide member.

8. Apparatus according to claim 1 including normally open electricalswitch contacts mounted in the path of movement in one direction of atleast one of said pushbuttons; and means carried by said one pushbuttonfor closing said contacts.

9. Apparatus according to claim 8 wherein at least one of said switchcontacts and said one pushbutton have cooperable detent means forreleasably latching said one pushbutton in contact closing relation.

10. Apparatus according to claim 8 including an additional pair ofnormally open contacts, and nonconductive detent means carried byanother of said push-.

buttons engageable with the contacts of said additional pair forlatching said another pushbutton.

11. Pushbutton control apparatus comprising valve means movable betweena plurality of positions; a slide member mounted for back and forthmovements along a path; means coupling said slide member to said valvemeans for moving the latter in response to movements of said slidemember; a plurality of reciprocable push buttons mounted for back andforth movements along a path lateral of the path of movement of saidslide member; cooperable means on said slide member and on each of saidpushbuttons for imparting movement to said slide member in a selecteddirection along its path in response to movement in one direction of anyselected one of said pushbuttons; and means independent of said slidemember and movable in the direction of movement of said pushbuttons formoving said selected one pushbutton in the opposite direction whenanother one of said pushbuttons is moved in said one direction.

12. Apparatus according to claim 11 wherein the cooperable means on saidslide member and said pushbuttons are so located that movement of saidslide member from one position to another in response to said movementof said selected one of said pushbuttons conditions the cooperable meanson said slide member and another of said pushbuttons to impart movementto said slide member in response to movement in one direction of saidanother pushbutton.

13. Apparatus according toclaim 11 including normally open switchcontacts engageable and closable by at least one of said pushbuttons inresponse to movement thereof in said one direction.

14. Apparatus according to claim 13 including cooperable detent means onsaid switch contacts and said one pushbutton for releasably latching thelatter in contact closing relation. v a

15. Apparatus according to claim 11 including motion transmitting means,and means coupling said motion transmitting means to all of saidpushbuttons for moving said one pushbutton in the opposite direction inresponse to movement in said one direction ofany other pushbutton.

l6.Apparatus according to claim 15 wherein said' motion transmittingmeans comprises a flexible cord spanning all of said pushbuttons andhaving a length in excess of the distance spanned by said pushbuttons.

17. Apparatus according to claim 16 wherein said cord extends alongsideeach of said pushbuttons and wherein said coupling means comprises apart carried by each of said pushbuttons and engaging said cord.

18. Apparatus according to claim 17 including guide means straddlingeach of said pushbuttons and engaging said cord.

19. Pushbutton control apparatus comprising valve means movable betweena plurality of positions; a single slide member mounted for back andforth movements along a path; means coupling said slide member to saidvalve member for moving the latter in response to movements of saidslide member; a plurality of reciprocable pushbuttons each mounted forback and forth movements between first and second positions along a pathlateral of the path of movement of said slide member; and cooperable cammeans on said slide member and on each of said pushbuttons, the cammeans on a selected one of said pushbuttons being engageable with thecam means on said slide member in response to movement of said onepushbutton in one i direction along its path from its first position toits second position and being operable to effect movement of said slidemember along its path from a first position to another position, the cammeans on another of said pushbuttons being engageable with the cam meanson said slide member in response to movement of said another pushbuttonin said one direction along its path from its first position to itssecond position and being operable to effect movement of said slidemember along its path from said second position, the cam means on saidslide member being operable to effect movement of said one pushbutton inthe opposite direction along its path toward its first position inresponse to movement of said slide member from said second position.

20. Apparatus according to claim 19 including switch means and switchoperating means carried by selected ones of said pushbuttons foroperating said switch means in response to movements of said selectedones of said pushbuttons between said first and second positions. a

21. Apparatus according to claim 20 including cooperable detent means onsaid switch means and'said switch operating means for'releasablylatching any of said selected ones of said pushbuttons in one of itssaid positions.

1. Pushbutton control apparatus comprising valve means movable between aplurality of positions; a slide member mounted for back and forthmovements along a path; means coupling said slide member to said valvemeans for moving the latter in response to movements of said slidemember; a plurality of pushbuttons mounted for back and forth movementsalong a path lateral of the path of movement of said slide member;cooperable means on said slide member and on each of said pushbuttonsengageable in response to movement in one direction of a selected one ofsaid pushbuttons to effect movement in a selected direction of saidslide member; means flexible in the path of movement of and spanningsaid pushbuttons and having a length greater than the distance spannedby said pushbuttons; and means coupling said flexible means to each ofsaid pushbuttons operable in response to movement in said one directionof any other one of said pushbuttons to impart movement of said selectedone of said pushbuttons in the opposite direction to disengage thecooperable means on said slide member and said selected one of saidpushbuttons.
 2. Apparatus according to claim 1 wherein said flexiblemeans comprises a cord.
 3. Apparatus according to claim 1 wherein theexcess length of said flexible means corresponds substantially to twicethe length of travel of a pushbutton.
 4. Apparatus according to claim 1including guide means straddling each of said pushbuttons and engagingsaid flexible means, said coupling means including a part carried byeach of said pushbuttons for engagement with said flexible means betweenadjacent guide means.
 5. Apparatus according to claim 4 wherein saidflexible means extends alongside all of said pushbuttons and whereinsaid part comprises a projection extending from and overlying saidflexible means.
 6. Apparatus according to claim 1 wherein saidcooperable means comprises a cam surface on said slide member in thepath of movement of and engageable by said selected one of saidpushbuttons.
 7. Apparatus according to claim 6, wherein said slidemember has a cam surface in the path of movement and engageable by eachof said pushbuttons, said cam surfaces being so contoured that theengagement between a selected one of said cam surfaces and theassociated pushbutton effects predetermined movement of said slidemember.
 8. Apparatus according to claim 1 including normally openelectrical switch contacts mounted in the path of movement in onedirection of at least one of said pushbuttons; and means carried by saidone pushbutton for closing said contacts.
 9. Apparatus according toclaim 8 wherein at least one of said switch contacts and said onepushbutton have cooperable detent means for releasably latching said onepushbutton in contact closing relation.
 10. Apparatus according to claim8 including an additional pair of normally open contacts, andnonconductive detent means carried by another of said pushbuttonsengageable with the contacts of said additional pair for latching saidanother pushbutton.
 11. Pushbutton control apparatus comprising valvemeans movable between a plurality of positions; a slide member mountedfor back and forth movements along a path; means coupling said slidemember to said valve means for moving the latter in response tomovements of said slide member; a plurality of reciprocable pushbuttonsmounted for back and forth movements along a path lateral of the path ofmovement of said slide member; cooperable means on said slide member andon each of said pushbuttons for imparting movement to said slide memberin a selected direction along its path in response to movement in onedirection of any selected one of said pushbuttons; and means independentof said slide member and movable in the direction of movement of saidpushbuttons for moving said selected one pushbutton in the oppositedirection when another one of said pushbuttons is moved in said onedirection.
 12. ApParatus according to claim 11 wherein the cooperablemeans on said slide member and said pushbuttons are so located thatmovement of said slide member from one position to another in responseto said movement of said selected one of said pushbuttons conditions thecooperable means on said slide member and another of said pushbuttons toimpart movement to said slide member in response to movement in onedirection of said another pushbutton.
 13. Apparatus according to claim11 including normally open switch contacts engageable and closable by atleast one of said pushbuttons in response to movement thereof in saidone direction.
 14. Apparatus according to claim 13 including cooperabledetent means on said switch contacts and said one pushbutton forreleasably latching the latter in contact closing relation. 15.Apparatus according to claim 11 including motion transmitting means, andmeans coupling said motion transmitting means to all of said pushbuttonsfor moving said one pushbutton in the opposite direction in response tomovement in said one direction of any other pushbutton.
 16. Apparatusaccording to claim 15 wherein said motion transmitting means comprises aflexible cord spanning all of said pushbuttons and having a length inexcess of the distance spanned by said pushbuttons.
 17. Apparatusaccording to claim 16 wherein said cord extends alongside each of saidpushbuttons and wherein said coupling means comprises a part carried byeach of said pushbuttons and engaging said cord.
 18. Apparatus accordingto claim 17 including guide means straddling each of said pushbuttonsand engaging said cord.
 19. Pushbutton control apparatus comprisingvalve means movable between a plurality of positions; a single slidemember mounted for back and forth movements along a path; means couplingsaid slide member to said valve member for moving the latter in responseto movements of said slide member; a plurality of reciprocablepushbuttons each mounted for back and forth movements between first andsecond positions along a path lateral of the path of movement of saidslide member; and cooperable cam means on said slide member and on eachof said pushbuttons, the cam means on a selected one of said pushbuttonsbeing engageable with the cam means on said slide member in response tomovement of said one pushbutton in one direction along its path from itsfirst position to its second position and being operable to effectmovement of said slide member along its path from a first position toanother position, the cam means on another of said pushbuttons beingengageable with the cam means on said slide member in response tomovement of said another pushbutton in said one direction along its pathfrom its first position to its second position and being operable toeffect movement of said slide member along its path from said secondposition, the cam means on said slide member being operable to effectmovement of said one pushbutton in the opposite direction along its pathtoward its first position in response to movement of said slide memberfrom said second position.
 20. Apparatus according to claim 19 includingswitch means and switch operating means carried by selected ones of saidpushbuttons for operating said switch means in response to movements ofsaid selected ones of said pushbuttons between said first and secondpositions.
 21. Apparatus according to claim 20 including cooperabledetent means on said switch means and said switch operating means forreleasably latching any of said selected ones of said pushbuttons in oneof its said positions.